The demand for long-lasting phosphors, which can be used for e.g. escape route signs, has been increasing due to widening of its applications since an MAl2O4:Eu type long-lasting phosphor (M representing an alkaline earth element) was developed (refer to, for example, Patent Document 1) by NEMOTO & CO., LTD in 1993. However, materials used for the production thereof are expensive and a production cost is relatively high so that they are sold at a high price and has not yet become widely used.    Patent Document 1: JP2,543,825B